1. Field of the Invention
The present invention relates to a three-dimensional image pickup optical system and a three-dimensional image pickup apparatus using the same, and more particularly, to a high-performance, compact, lightweight three-dimensional image pickup optical system having wide angle of field, high magnification, and bright F-number.
2. Description of the Related Art
Conventionally, there are proposed various three-dimensional image pickup optical apparatus and optical systems for obtaining parallax images. For instance, Japanese Patent Application Laid-Open No. 2001-166258 proposes a three-dimensional image pickup optical system that forms two different images having a parallax for left and right eyes alternately in time sequence on a single image pickup element.
In Japanese Patent Application Laid-Open No. 2001-166258, in order from an object side, a shutter for controlling a light beam, a first lens unit having a negative refractive power, and a reflection mirror as optical path deflecting unit are disposed for each of the left and right eyes. A combination optical element and a stop are disposed at an intersection of optical axes of the left and right eyes or at a position near the intersection, and a magnification-varying lens unit is disposed behind the combination optical element and the stop. Then, the shutters for the left and right eyes are opened and closed alternately in time sequence, to thereby obtain parallax images.
In the embodiment disclosed in Japanese Patent Application Laid-Open No. 2001-166258, a photographing angle of field is wide, that is, 35° to 36° in a half angle of field. However, a magnification-varying ratio is approximately 2, and an F-number at the telephoto end is approximately 4. Therefore, it is difficult to achieve both a high magnification and a bright F-number.